Results 61 to 70 of about 1,583 (160)

Signal to Noise Ratio (SNR) Enhancement Comparison of Impulse-, Coding- and Novel Linear-Frequency-Chirp-Based Optical Time Domain Reflectometry (OTDR) for Passive Optical Network (PON) Monitoring Based on Unique Combinations of Wavelength Selective Mirrors

Photonics, 2014
We compare optical time domain reflectometry (OTDR) techniques based on conventional single impulse, coding and linear frequency chirps concerning their signal to noise ratio (SNR) enhancements by measurements in a passive optical network (PON) with a ...
Christopher M. Bentz, Lars Baudzus, Peter M. Krummrich   +2 more
doaj   +1 more source

Optical Fiber Sensors for Safety and Maintenance Monitoring of Linear Infrastructure

Advanced Sensor Research, Volume 5, Issue 5, May 2026.
This review rigorously provides a thorough and detailed overview of the most recent innovations and advancements in the field of railway and pipeline infrastructure monitoring, accomplished through the implementation of cutting‐edge fiber sensing technologies, with a specific emphasis on its two principal technical branches, namely multipoint sensing ...
Shengnan Wu, Yue Cao, Xiaokun Qian, Jianling Wu, Armando Laudati, Vincenzo Romano Marrazzo, Maria Alessandra Cutolo, Giovanni Breglio, Andrea Cusano, Antonello Cutolo, Sailing He   +10 more
wiley   +1 more source

Magnetron Sputtering Synthesis of La‐Doped BiFeO3 Thin Films and Enhanced Exchange Bias in CoFeB/Bi1‐xLaxFeO3 Heterostructures

Advanced Physics Research, Volume 5, Issue 5, May 2026.
This study explores the epitaxial growth of high‐quality La‐doped BiFeO3 (BLFO) thin films at 550 °C using magnetron sputtering. The films exhibit good ferroelectric properties and low leakage current. A BLFO/CoFeB heterostructure is constructed, achieving an exchange bias field exceeding the coercive field at room temperature.
Zhiqin Zhou, Ligang Bai, Chen Qi, Xiaoyang Lin, Ivair Aparecido dos Santos, Gustavo Sanguino Dias, Luiz Fernanado Cótica, Weisheng Zhao, Yanxue Chen, Tianxiao Nie, Guodong Wei   +10 more
wiley   +1 more source

Crown Exposure Drives Sap Flow Variability Among Nearly Identical Trees in a Lowland Tropical Rainforest

Hydrological Processes, Volume 40, Issue 5, May 2026.
Contrary to expectations from upscaling in tropical forests, we found wide sap flow variability across and within individual trees of a homogeneous cohort in a tropical lowland rainforest (10 similar‐sized conspecific trees). Maximum sap flow from simultaneous readings differed up to 14‐fold between trees and averaged 52.5% within individual trees ...
Natalia de Aguiar‐Campos, Yoko F. Ishida, Will Edwards, Susan G. W. Laurance   +3 more
wiley   +1 more source

Optimizing soil moisture sensor installation depths and number of sensors for in situ monitoring networks

Vadose Zone Journal, Volume 25, Issue 3, May/June 2026.
Abstract Previously, developers of soil moisture monitoring networks have determined how many sensors to use and their installation depths with little objective guidance, which led to heavy reliance on suboptimal past precedents when deploying new networks. One such network, the Oklahoma Hydronet, is being developed to monitor water stored in the state'
Erik S. Krueger, Ali Ashrafi, Andres Patrignani, Briana M. Wyatt, Christopher A. Fiebrich, Cynthia M. Luttrell, Seyed Ali Azizi, Tyson E. Ochsner   +7 more
wiley   +1 more source

Nonlinearity Correction in OFDR System Using a Zero-Crossing Detection-Based Clock and Self-Reference

Sensors, 2019
Tuning nonlinearity of the laser is the main source of deterioration of the spatial resolution in optical frequency-domain reflectometry (OFDR) system. In this paper, we develop methods for tuning nonlinearity correction in an OFDR system from the aspect
Shiyuan Zhao, Jiwen Cui, Jiubin Tan
doaj   +1 more source

Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

Results in Physics, 2018
A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG) inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has
S.M. Popov, O.V. Butov, Y.K. Chamorovskiy, V.A. Isaev, A.O. Kolosovskiy, V.V. Voloshin, I.L. Vorob'ev, M.Yu. Vyatkin, P. Mégret, M. Odnoblyudov, D.A. Korobko, I.O. Zolotovskii, A.A. Fotiadi   +12 more
doaj   +1 more source

Remote phase-sensitive optical frequency domain reflectometry

Optics Express
We propose a common-path, self-referenced phase-sensitive optical frequency domain reflectometry (φ-OFDR) system capable of creating a remote sensing window at the far end of an ultra-long fiber. By utilizing the reflection from the fiber's far end as the local oscillator, the system inherently compensates for laser phase noise accumulated over the ...
Hongwei Li, Jiayan Wang, Zhang Xiong, Yanda Qu, TianFu Li, Shuaiqi Liu, Yongkang Dong   +6 more
openaire   +1 more source

Long-Range OFDR-Based Distributed Vibration Optical Fiber Sensor by Multicharacteristics of Rayleigh Scattering

IEEE Photonics Journal, 2017
We present a long-range optical frequency domain reflectometry (OFDR) based distributed vibration optical fiber sensor (DVOFS) by multicharacteristics of Rayleigh scattering.
Zhenyang Ding, Di Yang, Kun Liu, Junfeng Jiang, Yang Du, Bingkun Li, Minghao Shang, Tiegen Liu   +7 more
doaj   +1 more source

A Novel Method for the Processing of Optical Frequency Domain Reflectometry Traces

Optics
Optical frequency domain reflectometry (OFDR) is one of the key diagnostic tools for fiber optic components and circuits built on them. A low signal-to-noise ratio, resulting from the low intensity of backscattered signals, prevents the correct ...
Anton Krivosheev, Dmitriy Kambur, Artem Turov, Max Belokrylov, Yuri Konstantinov, Timur Agliullin, Konstantin Lipatnikov, Fedor Barkov   +7 more
doaj   +1 more source